19400478993 has 128 divisors (see below), whose sum is σ = 34725888000. Its totient is φ = 10472716800.

The previous prime is 19400478973. The next prime is 19400478997. The reversal of 19400478993 is 39987400491.

It is not a de Polignac number, because 19400478993 - 2⁵ = 19400478961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19400478997) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 61982205 + ... + 61982517.

It is an arithmetic number, because the mean of its divisors is an integer number (271296000).

Almost surely, 2^19400478993 is an apocalyptic number.

It is an amenable number.

19400478993 is a deficient number, since it is larger than the sum of its proper divisors (15325409007).

19400478993 is a wasteful number, since it uses less digits than its factorization.

19400478993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580 (or 574 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 54.

The spelling of 19400478993 in words is "nineteen billion, four hundred million, four hundred seventy-eight thousand, nine hundred ninety-three".